Railway-traffic-controlling apparatus



L. V. LEWIS RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Aug. 12', .1922

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UNITED STATES PATENT OFFICE.

LLOYD V, LEWIS, OF EDGEWOOD BOROUGH, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH 6'0 SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORA- 'lION OF PENNSYLVANIA.

RAILWAY-TRAFP'IC-CONTROLLING APPARATUS.

' Application filed August 12, 1922. Serial No. 581,470.

To all whom it may concern:

Be it known that I, LLOYD V. LEWIS, a citizen of the United States, residing at Edgewood Borough, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Railway-Traflic-Controlling Apparatus, of which the following is a specification.

-My invention relates to railway traffic controlling systems, and particularly to systems of the type wherein cab signals or speed governing apparatus, located on the railway train, are controlled by current supplied to. the train from the trackway.

I will describe several forms of ap aratus embodying 'my invention, and wiil then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a perspective view showing a track, a train thereon, and certain parts of one form of apparatus embodying my invention. Fig. 2 is a view, partly diagrammatic and partly in section, showing one form of train-carried apparatus embodying my invention. Fig. 3 is a diagrammatic view illustrating in simplified form the electrical connections of the apparatus shown in Fig. 2. Fig. 4 is a groupof curves illustrating the characteristics of the currents in certain parts of the apparatus shown in Figs. 2 and 3. Fig. 5 is a view showin a modification of the apparatus shown in ig. 2. Fi 6 is a diagrammatic view showing one orm of trackway apparatus embodying my invention. 1

Similar reference characters refer to similar parts in each of the several views. Referring first to Fig. 1, the reference characters 2 and 2, designate the track'rails of a railway, and V designates a vehicle, such as a car or train, traveling on the rails 2 and 2 in the direction indicated by the arrow 5. The vehicle V, which I'will hereinafter term a train, comprises a forward axle 3 provided with a pair of wheels 4, 4,

'stator windings 34 and 35.

through a ole-changer 12 and wires 13 and 14. It,wil be seen from the structure illustrated in Fig. 1 that when the polechan er 12 is in one position, direct current will ow through the forward axle 3 in the direction indicated by the arrows 6, whereas when the pole-changer 12 is reversed, direct current'will flow through the axle 3 in the direction opposite to that indicated by the arrows 6. This direct current, of course, flows through the two cores 7 and 8.

The magnetizable core 7 surrounding axle 3 is provided with-two coils 9 and 9 as shown in Fig. 2, whereas the core 8 is provided with two similar coils 10 and 10. These coils are constantly supplied with alternating current from a generator 25 and the frequency of this current I will herein assume to be 25 cycles per second. Generator 25 is constantly driven by a suitable prime mover on the train V, such for example as a direct current motor 15 supplied with energy from a storage battery 16.

The two coils 9 and 10 are connected in series in a circuit which passes from the generator 25, through wires 17 and 18, coil 9, wires 19 and 20, coil 10, and wires 21, 22, and 23 to the generator 25. The other coils 9 and 10' are also included in series in a circuit which passes from generator 25, through wires 17, 24 and29, coil 10, wires 26 and 27 coil 9*,and wires 28 and 23 to. generator 25. These circuits are so arranged that the magnetomotive forces created in each core 7 and 8.by the two coils thereon are in the same direction, whereas the currents induced in the axle 3 by the magnetomotive forces in the two cores 7 and 8 oppose each other.

The train is provided with a relay D which, as here shown, is of the induction motor type, comprising a rotor 60 and two One terminal of winding 34 is connected through wire 32 with the point 30 between the two coils 9 and 10, whereas the other terminal of the relay winding 34 is connected through wire '33 with the point 31 between the two coils 9 and 10. The other stator winding 35 of relay D is connected through wires 36 and 37 with an alternating current generator 50 which is constantly driven by the motor 15 and the frequency of which generator I will assume to be 50 cycles .per second, that is, twice the frequency of the generator 25.

Referring now to Fig. 3, it will be seen that the arrangement of the coils on the cores 7 and 8, the generator 25, and the relay winding 34, constitutes a Wheatstone bridge, the four legs of which are thecoils 9, 10, 9 and 10, the relay winding 34 being the bridge member of the bridge. When there is no direct current in the axle 3 of Figs. 1 and 2, the bridge is balanced so that no voltage is applied to the terminals of relay winding 34, and, consequently, no current flows in this winding. If, due to some defeet, the balance between the four coils is disturbed, alternating current of 25 cycles will flow through the relay winding 34, but the relay will not be energized because its other winding 35 is supplied with 50 cycle current and this relay can operate only when both windings are supplied with currents of the same frequency. If direct current flows through the axle 3, however,-it will produce a magnetic bias and distort the wave form of the alternating currents or voltages in the four coils carried by the cores 7 and 8, this bias at any instant producingan effect upon the two coils carried on core 7 opposite to that produced upon the two coilscarried on core 8. The resultant change inwave form from a sine wave is illustrated in Fig. 4, from which it will be seen that at any given instant if the alternating current inthe coils on core 7 is increased,'the alternating current in the coils on core 8 will be decreased. The result of this is that the current in coil 9 will be greater than that in coil 10, and the current in coil 9 will be greater than that in coil 10, and, referring to Fig. 3, an equalizing current will flow from point 30, through the relay winding 34-to point 31. One-half cycle later the current through the bridge arms will obviously be "in the opposite direction, and the currentsin coils 10 and 10 will be greaterthan those in coils 9 and 9, so that the equalizing current will then flow from point 30, through relay winding 34 to point 31, as before. This equalizing current is, therefore, in the same direction when the alternating current is a positive maximum and when it is a negative maximum, and hence it is of double the frequency of the generator 25, that is, the equalizing current is of 50 cycles per second. Fifty cycle current is then supplied to both of the stator windings of relay D, so that this relay will be energized in one direction or the other.

' The double frequency current supplied to relay winding .34 is a measure of the direct current through the axle 3. Reversing the polarity of the direct current through the axle, reverses the relative polarity of the double frequency current, and so the relay D will be energized in one direction or the other depending upon the directionin which the direct current flows through axle The apparatus interposed between the 25 cycle generator and the relay winding 34 may be termed astatic frequency doubler.

Referring now to Fig. 2, the relay D may be employed to control any suitable signal or apparatus of other form on the train. As shown in this view, the train is equipped with the signal S", and with speed control apparatus comprising-a high speed magnet H and a medium speed magnet M. The signal S includes three electric lamps G, Y and R, adapted when lighted to indicate respectively proceed, caution and stop. The speed controlling apparatus including the magnets H and M may be of any suitable or desired type, but inasmuch as this apparatus has nothing to do with the present invention it is omitted from the drawings.

When direct current of what I will term normal polarity is supplied to the axle 3, relay D will be energized in what I will term normal direction, so that its contact 38-39 is closed. The proceed lam-p G of signal S is then illuminated through a'circuit which passes from generator 25, through wires 23, 22, and 42, relay contact 3839, wire 43, proceed lamp G, and wires 44, 49, 24 and 17, to generator 25. At the same time the high speed magnet H is energized through wire 47. When direct current of reverse polarity is supplied to the axle 3, relay D is energized in reverse direction so that its contact 38.40 is closed, whereupon the caution lamp Y is lighted through this contact of the relay and wire 45; the medium speed magnet M is also energized through contact 38-40, and wires 45 and 48. When the supply of direct current to the axle 3 is discontinued, relay D becomes de-energized so that its back contact 38-41 is closed, whereupon the stoplampv R is lighted through this contact and wire 46; both of the magnets and M are then tie-energized.

Referring now to Fig. 5, the apparatus shown in this view is the same as that shown in Fig. 2, except that an electron tube amplifying device E is interposed between the frequency doubler and the relay winding 34. This amplifying device which, as here shown, is of the electron tube type, comprises a filament 55, a grid 56, and a plate 57, all enclosed in a vacuum tube 61. The

filament 55 is constantly heated by a bat tery 58. The primary 52 of a transformer 51 is connected across the points 30 and 31, and a condenser 53 is included in series with the primary 52, this primary circuitbeing preferably tuned to resonance at 50 cycles per second. The secondary 54 of transformer 51 is connected across the filacharacters 2 and 2" desi of potential across the points 30 and 31' will cause variations of considerably greater amplitude in-the current supplied to relay.

winding 34 by the battery 59. The apparatus shown in Fig. 5 may be preferable to that shown in Fig. 2 when low values of track circuit current are employed, such as current supplied by the usual track batteries in a direct current signaling system.

Referring .now to Fig. 6, the reference ate the track rails of a railway along whlch trafiic normally moves in the direction indicated by the arrow. These rails are divided by insulated joints 82 into a plurality of blocks of which only one block A-C is shown in the draw ing, it being understood that each block is equipped with apparatus similar to thatwhich is provided for block AC; This block is sub-divided into a rear section A-B and a forward section B-C.

The rear section AB is provided with a track relay T, which is connected across the rails adjacentthe entrance end .of the section. The forward section BC is provided-with two track relays T and T connected across the rails adjacent the entrance and exit ends of the section respectively. The supply of track circuit current to the rails of the rear section. is controlled by a line relay L, which relay in turn is controlled by both track relays T and T for the forward section and is supplied with current of normal or reverse polarity, depending on the condition of track relay T for the block next in advance of block AC. When relay T is closed, that is, when there is no train in the block in advance of A-C, the circuit for line relay L passes from the up er terminal of a battery 62, through the ont point of contact 63 of trackrelay T, contact 64 of track relay T contact 65 of track relay T winding of relay L, and thence through a com mon return conductor 0 (not shown in I full) .to the middle point of battery 62.

The current which is then supplied to line relay L is of normal polarity. When track relay T is open, that is, when the block immediately to the right of point C, is occupied by a train, the circuit for line relay-L is from the lower terminal of battery 62, through the back point of contact 63 of track relay T, and. then as before to the middle point of battery 62. Current of reverse polarity is then supplied to line relay L'. Line relay L includes vtwo polarized contacts 67 and 68 which constitute a pole-changer for connecting .a battery 66 in one direction or the other across the track rails of the rear setcion AB, this connection also including neutral 'contacts 69 and 70, so that when relay L is open, due to the presence of a train in the advance section BC, the supply of current to the rails of section A--B is discontinued. Current ofnormal or reverse polarity is supplied to the rails of section A-.-B frombattery 66 according as relay L is energized with current of normal or reverse polarity from battery '62.

-The advance section B-C is provided with two track batteries 73 and 74, located adjacent the entrance and the exit ends of this section, res ctively. When track relay Tis close track battery 74 is connected across the rails at the exit end of the section B C through contact of this relay, but when this relay is open battery 74 is disconnected from the rails. When track relay T is open, a line relay L is energized through the back point of' contact 71 of this track relay, and battery 73 is then connected across the rails of section BG at the entrance end of this section through contact 72 of relay L It will be seen, therefore, that battery 73 or battery 74 is connected with the rails of section B-C as track relay T for the next section to the right is open or closed. Both track relays T and T are closed by either battery- 73 or 741. v

The operation of the apparatus shown in Fig. 6 is as follows:

Assuming that the block to the right of block AC is unoccupied, a train equipped with the apparatus shown in Fig. 2 or'Fig. 5 entering block AC will receive current of normal polarity from battery 66 as long as the train occupies the rear section A'-B, and so aproceed indication will be given on the train. As the train passes into the advance section BC it will receive track circuit current of normal polarit from battery 74 and so the proceed indication will still be given on the train. If the block to the right of block AC is occupied, however, track relay T will be open so that gtion indication throughout the rear section AB. Track battery 74 will now be disconnected from the rails and track battery 73 will .be connected to the rails, so that as the train enters section B-C, its forward axle 3' will be shunted or cut off from battc'ry 73 by axle 3 and it will receive no current from the track rails, and, consequently. a stop indication will be given on the train. \Vhile the train is in section B-(-, track relays T and T will both be open, so that line relay L will be de-energized with the result that battery 66 is disconnected from the rails of the rear section A-B, so that a following train entering this section will receive a stop, indication.

As shown in Fig. 6, the block AC is provided with a signal S", which is located adjacent the entrance end of the block, and the block to the right of block AC is provided with a similar signal S Signal S is controlled by track relay T and by a line relay F which line relay in turn is controlledby a polarizedcontact 76 in line relay L. Relay F is closed when line relay L is energized in normal direction but not when line relay L is energized in reverse direction or is de-energized. Signal S is provided with a caution indication circuit. which passes from terminal B of a suitable source of current through the front point of contact 77 of track relay T, wire 78, and operating mechanism of signal S to terminal ot' the same source of current. This signal is further provided with a proceed indication circuit including contact 77 of track relay T, wire 79, contact 80 of line relay F", and wire. 81. It will be seen from the foregoing that when block AC and the block next to the right are unoccupied, relay I) is energized in nor mal direction, so that line relay F is closed and signal S consequently indicates proceed. \Vhen the block to the right of AC is occupied, line relay L is energized in-reverse direction. so that line relay F is open and signal S then indicates caution, assuming, of course, that block AU is unoccupied. lVhen block AC is occupied, track relay T is open, so that signal S then indicates stop. It will be noted that track relay T is open when either section of block A-C is occupied; that is, when a train is in section AB the supply of current to track relay T is shunted by the wheels and axles of such train. whereas, when the train is in section BC track relays T and T are both'open, so that line relay L is open and the supply of current to section A B is then discontinued by the contacts 69 and 70 of relay L.

Although I have herein shownand described only certain forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a railway vehicle, two magnetizable cores on an axle thereof, two coils on each core, a circuit on said vehicle including a first source of alternating current and two multiple branches each including in series one coil on each core, a relay on said vehicle having a winding controlled by the difference of potential between a point in said first branch between the two coils therein and a point in said second branch between the two coils therein, said relay including asecond winding supplied with alternating current from a vehicle carried source having twice the frequency of the first source, vehicle governing apparatus controlled by said relay, and means located in the trackway for passing direct current through said vehicle axle.

2. In combination, a railway vehicle, two magnetizable cores on an axle thereof, two coils on each core, a circuit on said vehicle including a first source of alternating current and two multiple branches each including in series one coil on each core, said coils being so connected that at any given instant the fluxes produced by the two coils on each core are in the same direction butthe electromotive forces produced in said axle by said two cores oppose each other, a relay on said vehicle having a winding controlled by the difference of potential between a point in said first branch between the two coils therein and a point in said second branch between the two coils therein, said relay including a second winding supplied with alternating current from a vehicle carried source having twice the frequency of the first source, vehicle governing apparatus controlledby said relay, and means located in the trackway for passing direct current through said vehicle axle.

3. In combination, a railway vehicle, two

magnetizable cores on an axle' thereof, two

coils on each core, a circuit on said vehicle including a first source of alternating current and two multiple branches each includ ing in series one coil on each core, a relay on said vehicle having a winding, controlled by the difference of potential between a point in said firstbranch between the two coils therein and a point in said second branch between the two coils therein, said relay including a second winding supplied with alternating current from a vehicle carried source having twice the frequency of the first source, vehicle governing apparatus controlled by said relay, and means located in the trackway for passing direct current through said vehicle axle in one direction or the other.

4. In combination, a. railway vehicle, two magnetizable cores on an axle thereof, two coils on each core, a circuit on said vehicle including a first source of alternating current and two multiple branches each including in series one coil on each core, a relay on said vehicle having a winding controlled by the difference of potential between a point in said first branch between the two coils therein and a point in said second branch between the two coils therein, said relay including a second winding supplied with alternating current from a vehicle carried source having twice the frequency of the first source, vehicle governing apparatus controlled by said relay, and means located in the traclrway and controlled by traffic conditions in advance for passing direct current through said vehicle-axle in one direction under clear trafiic conditions and in the opposite direction under caution trailic conditions.-

5. In combination, a railway vehicle, two mag'netizable cores on an axle thereof, two coils on each core, a circuit on said vehicle including a first source of alternating current and two multiple branches each including in series one coil on each core, a relay on said vehicle havin a winding controlled by the difference 0 potential between a 6 point in said first branch between the two coils therein and a point in said second branch between the two coils therein, said relay including a second winding supplied with alternating current from a vehicle carried source havin twice the frequency of the first source, ve 'cle governing apparatus controlled by said relay, and means located in the trackway and controlled by trafiic conditions in advance for passing direct current through said vehicle axle.

6. In combination, a railway vehicle, two

magnetizable cores on an axle thereof, two coils on each core, a circuit on said vehlcle including a first source of alternating cur.-

rent and two multiple branches each including in series one ,coil on each core,-

amplifying means on the vehicle having an input circuit controlled by the potential difference between two points in said two branches respectively each point being between the two coils in the branch, a relay on the vehicle having two windings on of which is supplied with current by the output circuit of said amplifying means, said relay including a second win ing su plied with alternating current from a vehic e carried source having twice the frequency of the first source, vehicle governing apparatus controlled by said relay, and means located in the trackway for passing direct current throug hsaid vehicle axle.

7 In combination, a railway vehicle, two

sources of alternating current thereon differing in frequency, a relay having two windings associated respectively with said two sources, trackway means for changin the frequency of the current from one o said sources to the frequency of the other source, and governing means on the vehicle controlled by said relay.

8. In combination, a railway vehicle, two sources of alternating current thereon differing in frequency, a relay hav ng two windings associated respectively with said two sources, means interposed between one of said sources and the associated relay winding and responsive to the presence of direct current for changing the frequency delivered to such winding to the frequency of the other source, trackway means for supplying direct current to said frequency charging means, and governing means on said vehicle. controlled by said relay.

9. In combination, a railway vehicle, two sources of alternating current thereon differlng in frequency, means located partly on the vehicle, and partly in the trackway for supplying a receiving circuit with current from one of said sources modified into the frequency of the other source, and governing means on the vehicle controlled by said receiving circuit and by the other source.

10. In combination, a stretch of railway track divided into blocks each comprising a rear and a forward section; and means for suppllying direct current of normal polarity to t e rails of both sections of a block at the exit end thereof when the block next.

in advance is clear, and for discontinuing the su ply of direct current from the exit end 0 the forward section andsupplying direct current of reverse polarity to the rear section 'whenthe-block next in advance is occupied.

11. In combination, a stretch of railway track divided into blocks each having a rear and. a forward section, a track relay connected with the rails of each rear section, at the entrance end thereof, two track relays connected with the rails of each forward section at the entrance and exit ends respectively, a line relay for each rear section controlled by the track relays for the, associated forwardsection and supplied with current of, normal or reverse polarity according as the first track relay for the next block in when the block next in advance is unoccupied but not when it is occupied, and means for supplying direct current to the'rails of each forward section at the entrance end' thereof when the block next in advance is occupied.

12. In combination, a railway vehicle, a

static frequency doubler thereon, a source of alternating current on the vehicle for sand frequency doubler, means located in the ,trackway for supplying direct current to doubler, and governing said frequenc vehicle controlled bysaid means on sai doubler. A

' 13. In comblnation, arailway vehlcle, a

first source of alternating current thereon, a static frequency doubler on said vehicle supplied With current from said first source, a second source of alternating current on said vehicle the frequency of which is twice that of said first source, trackway means for supplying direct current to said frequency doubler, and governing means on said vehicle controlled jointly by said frequency doubler and by said second source of alternating current.

14. In combination, a railway vehicle, a first source of alternating current thereon, a static frequency doubler on said vehicle supplied with current from said first source, a second source of alternating current on said vehicle the frequency of which is twice that of said first source, trackway means for supplying direct current to said frequency doubler, a relay on said vehicle having two windings one of which is supplied with current from said frequency doubler and the other With current from said second source, and governing means on said vehicle controlled by said relay.

15. In combination, a railway vehicle, a static frequency doubler thereon, a source of alternating current on the vehicle for said frequency doubler, means located in the trackway for supplying direct current to said frequency doubler, governing means on said vehicle controlled by said frequency doubler, and amplifying means interposed between said doubler and said governing means.

In testimony whereof I affix my signature.

LLOYD V. LEWIS. 

